Structural Evolution of Boron Clusters on Ag(111) Surfaces - From Atomic Chains to Triangular Sheets with Hexagonal...

Area of Science:

• 2D materials science
• Surface chemistry
• Computational materials science

Background:

• Borophene exhibits polymorphism, unlike graphene.
• Borophene's structure, including hexagonal holes (HHs) and triangle ratios, is substrate-dependent.
• Understanding borophene nucleation on metal surfaces is crucial for its synthesis.

Purpose of the Study:

• To investigate the structural evolution of boron clusters (B_N) on Ag(111) surfaces.
• To elucidate the nucleation process of 2D borophene sheets.
• To understand the role of substrate interactions in borophene formation.

Main Methods:

• Systematic exploration of B_N clusters (N=1–36) on Ag(111) using computational calculations.
• Analysis of structural transitions from compact triangular lattices to mixed triangular-hexagonal lattices.
• Investigation of charge transfer mechanisms contributing to cluster stability.

Main Results:

• Boron cluster structures evolve from compact triangular lattices to mixed lattices with increasing size.
• The first single hexagonal hole (HH) appears at N=12, and the first double HH at N=27.
• Charge transfer between boron clusters and the Ag(111) substrate enhances the stability of mixed structures.

Conclusions:

• The study provides insights into the initial nucleation stages of borophene growth.
• Substrate-induced charge transfer plays a key role in stabilizing complex borophene structures.
• Understanding these fundamental processes is vital for controlled synthesis of borophene.